fly ash/plastic synthetic aggregate for construction material

The samples were washed and then oven dried to a constant mass at 110 ± 5°C. The test
sample was then placed into the Los Angeles testing machine along with the six steel
charges, as shown in Figure 13. The machine was then rotated at a speed of
approximately 32 revolutions per minute for 500 revolutions. The material was then
removed from the testing apparatus and preliminarily separated using a No. 8 sieve (2.36
mm spacing). The finer portion was then sieved through a No. 12 (1.70 mm) sieve. The
material coarser than the No. 12 sieve was then oven dried to a constant mass at 110 ±
5°C. The mass of the oven-dried material was then measured and recorded, and the Los
Angeles Abrasion Number was calculated using the following equation:
⎛ M
sample(
original)
sample(
coarse)
LA Abrasion Number = ⎜
⎟( 100% )
⎝
M
− M
sample(
coarse)
⎞
⎠
where M sample(original) is the total mass of the original sample (g) and M sample(coarse) is the
coarse portion of the aggregate larger than the No. 12 sieve (1.77 mm) after 500
revolutions.
The LA Abrasion Test was conducted on three coarse aggregates; N 1 , E, and C 2 80H. LA
Abrasion #’s were calculated using the above equation and the values are presented in
Table 5.
Table 6: LA Abrasion #’s for the Coarse Aggregates
Aggregate LA Abrasion #
N 14.8
E 27.9
C 2 80H SLA 6.6
6.4.1 Test Results
The Los Angeles Abrasion test results are presented in Table 5. The tumbling and
dropping of the aggregates along with the steel charges resulted in abrasion and attrition
of the aggregate. The expanded clay lightweight aggregate, E, performed poorly as
compared with the other two samples, as can be seen from the comparison between the
initial gradation and gradation after the LA Abrasion test presented in Figure 14(a);
The normal density aggregate, N, performed quite well; the dense structure of the
aggregate is relatively resistant to abrasion and effective in absorbing energy dissipated
during impact with the steel charges. A comparison between the initial gradation and
gradation after the LA Abrasion test for N is presented in Figure 14(b) and shows how
the fines content increases.
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